Читать книгу Astrobiology - Charles S. Cockell - Страница 68

1 It is sometimes said that the existence of life requires covalent bonding. Discuss this statement.

2 Describe an example of the use of hydrogen bonding in living things. Why is this bonding type used in certain biological contexts and not others?

3 Explain the concept of an isotope with reference to atomic structure.

4 Why are solid metals not used in living things?

5 Draw a phase diagram of water and use it to explain some of the main features concerning the history of water on the surface of Mars. Use it to explain why the subsurface might be a better place to look for liquid water today.

6 There are extreme states of matter in the Universe, such as degenerate matter. Discuss whether you think a living thing could be constructed from degenerate matter.

7 Write a short essay to compare and contrast the use of ionic, covalent, hydrogen, and Van der Waals interactions in living things with an example for each of how they bond together atomic and molecular structures.

8 Describe the difference between an emission and absorption spectrum, explaining how they are produced by changes in electron energies. How might such spectra be used to look for gases produced by life in the atmosphere of an extrasolar planet?